All Questions

Previously I have asked Space based active optical sensors for maritime surveillance. As a follow on, No SAR sensor is allowed. The suggestion is to use an RF scanner and verify that against collected ...

I am a 3rd year electrical and electronics engineerincg under graduate student from India. I want to join space industry furthur. How should i select my majors and projects so that i could achieve ...

I need to compute the footprint (ground area that its transponders offer coverage) of beam diameter. Given different frequencies, distance between a satellite and ground station. I have found the same ...

With the discussion that took place on answer(s) to How to calculate cone angle between two satellites given their look angles? I would like to ask if my proposal solving that question works like ...

Will launched time of a laser satellite teminal affect to transmission parameters, as data rate, power …? As I know , the main limitation of lasercom is a direct line-of-sight path exists between a ...

I remember watching a few videos awhile back talking about origami designs in spacecraft: Origami in Space: BYU-designed solar arrays inspired by origami Engineering with Origami I've only done a ...

I was thinking for quite a while about sending this question to Maria Zuber's e-mail address (she was the principal investigator of the GRAIL mission to map the Moon's gravity field), but then I ...

Talking about aerodynamic forces in a model rocket, I believe that Lift and Drag are the components of a net force which acts on the Center of pressure. Knowing this, could I affirm that the net ...

USGS.gov's Landsat 9: Payloads stacked atop Atlas V for launch includes the following: A fourth and final burn by the Centaur's RL10C-1 cryogenic main engine executes a deorbit maneuver nearly three ...

For a rocket of: fuel mass $m_f$ = 6 kg, Thrust = 3.1 KN, (vs 4K using reducing catalyst to delay burn time) total powered burn time, $t_b$ = 3.5 s, (using reducing catalyst vs 1.8 sec) This ...

Do the two terms mean the same? mass production rate, mass flow rate and mass consumption rate in a solid propellant rockets.

Here is the pic for here and other sources. You see that lines at leff ("claw") are thicker than lines ar right ("base"). Why? Intuitively it seems that is should be opposite!

Background For the project discussed in Space based active optical sensors for maritime surveillance the concern seems to be that SAR is off the table because a low inclination orbit is in eclipse ...

Background Recently I came across a company called ASTS that claims they will be able to launch LEO satellites with the capability to talk with regular mobile phones. I initially wrote their claims ...

Did SpaceX made public their estimates for Starship orbital vehicle heat shield maximum heating (and overall reentry heating profile) during orbital reentry on Earth and same for Super-heavy booster ...

Is there any way to artificially make salts for humans colonizing planets on a long term basis? It is given that the exoplanet has a water source. So do we hope for the best that it has salt present ...

I am designing a CubeSat. The size is yet to be decided as it is based on the sensor. The mission is maritime surveillance (illegal fishing). The payload should be capable of detecting the vessels. ...

The block quote in this answer to Has Curiosity ever taken a good hard look at the dirt covering its top surface? Can it? Have individual particles been sized? says that at a focus distance of 2.5 ...

My understanding of orbital mechanics is that delta-v is the most useful notion of ability to change orbits in space, akin to energy being the most useful notion of the ability to do work. But if ...

This is really simple, but i've never seen it discussed. One piloted the Apollo LEM standing up, without many restraints. But before the LEM ignited the descent engine, it was practically in free fall....

In many rocket engines i see that the thrust chamber and a small part of the nozzle are one piece. Does anyone knows if there's a formula which determines what portion of the nozzle is A ? and how ...

Any Kerbal Space Program player will know that burns prograde and retrograde to the velocity vector are most efficient closest to the body being orbited, while burns normal and anti-normal are most ...

A common fuel amongst rockets is that of the combination of cryogenic liquid hydrogen and liquid oxygen. I looked at the design of a simple rocket using this cocktail that is the propellant and found ...

In Scott Kelley's memoir "Endurance," he describes how challenging it is to navigate the exterior of ISS when in Earth's shadow, and he mentions that his Russian colleagues would just stay ...

This one can be a very short and easy question, but I wanna know the proper answer of them.. Few days ago I got a questions like: "What kind of perturbation(s) can cause drift on RAAN value of a ...

For RF we have the frequency allocation table, where the RF spectrum is regulated. Optical has big bandwidth, there is a lot of frequency space. How do we regulate optical spectrum? I didnt find any ...

The first version of this question is here. I have read the article "Optical communications work best over relatively short distances in space." by Toyoshima, M., Leeb, W., Kunimori, H. and ...

In this answer @uhoh notes: The Starlinks currently have three types of internet-related communication: downwards with customers fixed on the Earth's surface below the satellites (except an ...

Can anyone give me a lead on where to find the exact dimensions of the diagonal braces used on the original (Apollo-Era) Saturn V Launch Umbilical Tower (LUT)? In fact, while we are at it, I am ...

Is it better to use N2O or Oxygen and where could I buy it in Sweden?

I'm doing research on life support systems for the design of a Martian scientific base, and I'm having trouble finding information about the specifics racks that keep pressure stable inside the ISS. I ...

Curiosity had an instrument called SAM onboard that did gas chromatography and mass spectrometry. Do any of the instruments on Perseverance include these capabilities? If not, why were they deemed ...

I understand the upper stage separates with the use of pneumatic pushers, but what settles the propellants in the upper stage tanks so that the propellant is pushed back to the intake? The pushers ...

A MSN article states : Perseverance, nicknamed Perky Is this nickname actually used for Perseverance? By whom? Do the people at NASA colloquially call the rover Perky?

For a rocket of: mass, $m$ = 25kg, dry mass $m_f$ = 19 kg, Thrust = 2.1 KN, total powered burn time, $t_b$ = 3.5 s, $I_{sp}$ = 129 I get powered burn height = 549 m and total time to max ht of 5506 ...

What all are the factors that should be taken in consideration while growing plants in an alien planet?(The planet is deficient of nutrients and receives infra red radiations)

If we find a hypothetical Earth-like planet A with a rocky terrain that we could colonize, how would we go about planting the first plants, knowing that there is a deficient of nutrients and the ...

To chill down an engine, cryogenic propellant is pushed through the engine. This is fine for the first stage because the chill down propellant can just flow out the nozzle and on to the ground/the ...

Roughly by how many degrees does the strongback tilt back during liftoff? does the angle have any significance other than avoiding collision?

My recent question and the related ones made me wonder which space stations in history used Torque Equilibrium Attitude so that one side always faced the Earth and the other faced zenith, and which ...

In this article astronaut Clayton C. Anderson states that on the ISS the windows "mosty face Earth, which means that it is only possible to see the stars at the very edges of the windows, and ...

On the NASA website, it says that the propeller on Ingenuity will need to spin faster than what has been done before during all of the previous tests to accommodate for the rarefied atmosphere during ...

Micro-G is known to be detrimental to health in the long-term. However, the Moon is at $\frac{1}{6}$ G (while Mars is at ~$\frac{3}{8}$ G). Is $\frac{1}{6}$ G enough for humans to remain healthy in ...

Soyuz spacecraft has various survival equipment for different cases of emergency landing. The cases include water landing, desert landing, snow winter landing (crews have special winter suits). They ...

In the video on the NASA website, the speaker says that in SuperCam, we use a combination of lasers Why does the SuperCam need multiple lasers? Did ChemCam also have several lasers?

The NASA website mentions that the SuperCam onboard Perseverance can measure the air. How does it do this? Does it use LIBS? Is the SuperCam more apt at doing these measures than a regular camera?

I was looking online for a profile depicting the Dragon re-entry similar to those showing the launch and first stage re-entry (e.g. https://www.elonx.net/wp-content/uploads/...

First stages of Atlas V rocket used to be transported by air on Antonov-124 cargo aircraft. Later Lockheed-Martin switched to transporting by water. Why C-5 Galaxy wasn't used instead of An-124? ...

As a successor to the Soyuz program, Russia is currently planning the Oryol/Federatsiya, at first for LEO flights and eventually for lunar ones. Russia wants to build a lunar space station (similar to ...

What is the cost to NASA per launch to ISS of Starliner vs Crew Dragon? The Crew Dragon flights uses the SpaceX Falcon 9-FT with the first stage reusable, along with the partially reusable Crew ...